This application claims the priority of Germany, filed Dec. 16, 2000, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a method and a device for controlling the brake system of a vehicle.
DE-A-195 24 939 suggests a method and a device for controlling the brake system of a vehicle in which an automatic braking operation is initiated when a threshold value is exceeded by the rate of change of the input pressure, wherein the threshold value becomes smaller as the potential for danger increases.
DE-A-197 12 859 describes a brake control system for motor vehicles. In this brake control system, a pressure sensor is provided for detecting the initial pressure and the initial pressure gradient. When the initial pressure exceeds a first threshold value and the initial pressure gradient a second threshold value, a control device switches into auxiliary control mode. In this auxiliary control mode, a quick pressure build-up in the wheel brake cylinder and thereby the maximum possible delay and shortest possible stopping distance are achieved.
In the described known methods, the braking operation is supported as a function of exceeding certain threshold values. That is, a clear limit is provided for initiating the braking support operation. Below this threshold no braking support operation is provided, and above this threshold a full-scale braking support operation occurs in emergency braking situations. The transition from a normal braking phase into the support phase occurs hereby suddenly. It is difficult to set or establish a suitable limit value. Too low a threshold value can trigger an emergency braking process even in non-critical situations that is not desired by the driver. Too high a threshold value in turn remains without effect if, for example, unskilled drivers in critical situations (or apparently non-critical situations) brake too timidly and therefore do not reach the threshold value, initiating no emergency braking operation at all or too late.